“Wenzel and Richter, the latter… of most pronounced mathematical temperament, laid the foundations of stoichiometry, or "the art of measuring the chemical elements."”

Introduction
Higher Mathematics for Chemical Students (1911)
Context: The results of a scrutiny of the materials of chemical science from a mathematical standpoint are pronounced in two directions. In the first we observe crude, qualitative notions, such as fire-stuff, or phlogiston, destroyed; and at the same time we perceive definite measurable quantities such as fixed air, or oxygen, taking their place. In the second direction we notice the establishment of generalizations, laws, or theories, in which a mass of quantitative data is reduced to order and made intelligible. Such are the law of conservation of matter, the laws of chemical combination, and the atomic theory.

1881, A Defence of Atheism: A lecture delivered in Mercantile Hall, Boston on 10 April, 1861, p. 4
A Defence of Atheism

quote, p. 378
posthumous publications, El Lissitzky, El Lissitzky : Life, Letters, Texts (1967; 1980)

"What is War?" (1924)

Source: Living Systems: Basic Concepts (1969), p. 51

Introduction
Higher Mathematics for Chemical Students (1911)

Preface p. v
A History of Greek Mathematics (1921) Vol. 1. From Thales to Euclid

Nobel lecture (12 December 1938)

As quoted by Arnold B. Chace, in Benjamin Peirce, 1809-1880 : Biographical Sketch and Bibliography (1925) by R. C. Archibald.